sdcard: Initial support for SD cards on PCI SDHCI controllers on QEMU

This adds basic read/write support for SD cards emulated by QEMU.
This code is not expected to work on real hardware, because the
current controller and card initialization is not robust.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/Makefile b/Makefile
index 1cff1d0..a84a5f7 100644
--- a/Makefile
+++ b/Makefile
@@ -39,7 +39,7 @@
 SRC16=$(SRCBOTH)
 SRC32FLAT=$(SRCBOTH) post.c memmap.c malloc.c romfile.c x86.c optionroms.c \
     pmm.c font.c boot.c bootsplash.c jpeg.c bmp.c \
-    hw/ahci.c hw/pvscsi.c hw/usb-xhci.c hw/usb-hub.c \
+    hw/ahci.c hw/pvscsi.c hw/usb-xhci.c hw/usb-hub.c hw/sdcard.c \
     fw/coreboot.c fw/lzmadecode.c fw/csm.c fw/biostables.c \
     fw/paravirt.c fw/shadow.c fw/pciinit.c fw/smm.c fw/smp.c fw/mtrr.c fw/xen.c \
     fw/acpi.c fw/mptable.c fw/pirtable.c fw/smbios.c fw/romfile_loader.c
diff --git a/src/Kconfig b/src/Kconfig
index a1c0c1e..45ca59c 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -159,6 +159,12 @@
         default y
         help
             Support for AHCI disk code.
+    config SDCARD
+        depends on DRIVES && QEMU_HARDWARE
+        bool "SD controllers"
+        default y
+        help
+            Support for SD cards on PCI host controllers.
     config VIRTIO_BLK
         depends on DRIVES && QEMU_HARDWARE
         bool "virtio-blk controllers"
diff --git a/src/block.c b/src/block.c
index 7892be5..c6d53c1 100644
--- a/src/block.c
+++ b/src/block.c
@@ -534,6 +534,11 @@
         ret = call32(_cfunc32flat_process_atapi_op
                      , (u32)MAKE_FLATPTR(GET_SEG(SS), op), DISK_RET_EPARAM);
         break;
+    case DTYPE_SDCARD: ;
+        extern void _cfunc32flat_process_sdcard_op(void);
+        ret = call32(_cfunc32flat_process_sdcard_op
+                     , (u32)MAKE_FLATPTR(GET_SEG(SS), op), DISK_RET_EPARAM);
+        break;
     case DTYPE_USB:
     case DTYPE_UAS:
     case DTYPE_VIRTIO_SCSI:
diff --git a/src/block.h b/src/block.h
index aa01ed7..8182288 100644
--- a/src/block.h
+++ b/src/block.h
@@ -71,6 +71,7 @@
 #define DTYPE_ESP_SCSI     0x81
 #define DTYPE_MEGASAS      0x82
 #define DTYPE_PVSCSI       0x83
+#define DTYPE_SDCARD       0x90
 
 #define MAXDESCSIZE 80
 
diff --git a/src/hw/sdcard.c b/src/hw/sdcard.c
new file mode 100644
index 0000000..6ff93c8
--- /dev/null
+++ b/src/hw/sdcard.c
@@ -0,0 +1,321 @@
+// PCI SD Host Controller Interface
+//
+// Copyright (C) 2014  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "block.h" // struct drive_s
+#include "fw/paravirt.h" // runningOnQEMU
+#include "malloc.h" // malloc_fseg
+#include "output.h" // znprintf
+#include "pci.h" // pci_config_readl
+#include "pci_ids.h" // PCI_CLASS_SYSTEM_SDHCI
+#include "pci_regs.h" // PCI_BASE_ADDRESS_0
+#include "stacks.h" // wait_preempt
+#include "std/disk.h" // DISK_RET_SUCCESS
+#include "string.h" // memset
+#include "util.h" // boot_add_hd
+#include "x86.h" // writel
+
+// SDHCI MMIO registers
+struct sdhci_s {
+    u32 sdma_addr;
+    u16 block_size;
+    u16 block_count;
+    u32 arg;
+    u16 transfer_mode;
+    u16 cmd;
+    u32 response[4];
+    u32 data;
+    u32 present_state;
+    u8 host_control;
+    u8 power_control;
+    u8 block_gap_control;
+    u8 wakeup_control;
+    u16 clock_control;
+    u8 timeout_control;
+    u8 software_reset;
+    u16 irq_status;
+    u16 error_irq_status;
+    u16 irq_enable;
+    u16 error_irq_enable;
+    u16 irq_signal;
+    u16 error_signal;
+    u16 auto_cmd12;
+    u8 pad_3E[2];
+    u64 cap;
+    u64 max_current;
+    u16 force_auto_cmd12;
+    u16 force_error;
+    u8 adma_error;
+    u8 pad_55[3];
+    u64 adma_addr;
+    u8 pad_60[156];
+    u16 slot_irq;
+    u16 controller_version;
+} PACKED;
+
+// SDHCI commands
+#define SC_ALL_SEND_CID         ((2<<8) | 0x21)
+#define SC_SEND_RELATIVE_ADDR   ((3<<8) | 0x22)
+#define SC_SELECT_DESELECT_CARD ((7<<8) | 0x23)
+#define SC_READ_SINGLE          ((17<<8) | 0x22)
+#define SC_READ_MULTIPLE        ((18<<8) | 0x22)
+#define SC_WRITE_SINGLE         ((24<<8) | 0x22)
+#define SC_WRITE_MULTIPLE       ((25<<8) | 0x22)
+#define SC_APP_CMD              ((55<<8) | 0x22)
+#define SC_APP_SEND_OP_COND ((41<<8) | 0x22)
+
+// SDHCI irqs
+#define SI_CMD_COMPLETE (1<<0)
+#define SI_TRANS_DONE   (1<<1)
+#define SI_WRITE_READY  (1<<4)
+#define SI_READ_READY   (1<<5)
+
+// SDHCI present_state flags
+#define SP_CMD_INHIBIT (1<<0)
+#define SP_DAT_INHIBIT (1<<1)
+
+// SDHCI transfer_mode flags
+#define ST_BLOCKCOUNT (1<<1)
+#define ST_AUTO_CMD12 (1<<2)
+#define ST_READ       (1<<4)
+#define ST_MULTIPLE   (1<<5)
+
+// SDHCI result flags
+#define SR_OCR_CCS (1<<30)
+
+// SDHCI timeouts
+#define SDHCI_PIO_TIMEOUT      1000  // XXX - these are just made up
+#define SDHCI_TRANSFER_TIMEOUT 10000
+
+// Internal 'struct drive_s' storage for a detected card
+struct sddrive_s {
+    struct drive_s drive;
+    struct sdhci_s *regs;
+    int card_type;
+};
+
+// SD card types
+#define SF_MMC  0
+#define SF_SDSC 1
+#define SF_SDHC 2
+
+// Repeatedly read a u16 register until the specific value is found
+static int
+waitw(u16 *reg, u16 mask, u16 value, u32 end)
+{
+    for (;;) {
+        u16 v = readw(reg);
+        if ((v & mask) == value)
+            return 0;
+        if (timer_check(end)) {
+            warn_timeout();
+            return -1;
+        }
+        yield();
+    }
+}
+
+// Send a command to the card.
+static int
+sdcard_pio(struct sdhci_s *regs, int cmd, u32 *param)
+{
+    u32 end = timer_calc(SDHCI_PIO_TIMEOUT);
+    u16 busyf = SP_CMD_INHIBIT | ((cmd & 0x03) == 0x03 ? SP_DAT_INHIBIT : 0);
+    int ret = waitw((u16*)&regs->present_state, busyf, 0, end);
+    if (ret)
+        return ret;
+    // Send command
+    writel(&regs->arg, *param);
+    writew(&regs->cmd, cmd);
+    ret = waitw(&regs->irq_status, SI_CMD_COMPLETE, SI_CMD_COMPLETE, end);
+    if (ret)
+        return ret;
+    writew(&regs->irq_status, SI_CMD_COMPLETE);
+    // Read response
+    memcpy(param, regs->response, sizeof(regs->response));
+    return 0;
+}
+
+// Send an "app specific" command to the card.
+static int
+sdcard_pio_app(struct sdhci_s *regs, int cmd, u32 *param)
+{
+    u32 aparam[4] = {};
+    int ret = sdcard_pio(regs, SC_APP_CMD, aparam);
+    if (ret)
+        return ret;
+    return sdcard_pio(regs, cmd, param);
+}
+
+// Send a command to the card which transfers data.
+static int
+sdcard_pio_transfer(struct sddrive_s *drive, int cmd, u32 addr
+                    , void *data, int count)
+{
+    // Send command
+    writel(&drive->regs->block_size, DISK_SECTOR_SIZE);
+    writew(&drive->regs->block_count, count); // XXX - SC_SET_BLOCK_COUNT?
+    int isread = cmd != SC_WRITE_SINGLE && cmd != SC_WRITE_MULTIPLE;
+    u16 tmode = ((count > 1 ? ST_MULTIPLE|ST_AUTO_CMD12|ST_BLOCKCOUNT : 0)
+                 | (isread ? ST_READ : 0));
+    writew(&drive->regs->transfer_mode, tmode);
+    if (drive->card_type < SF_SDHC)
+        addr *= DISK_SECTOR_SIZE;
+    u32 param[4] = { addr };
+    int ret = sdcard_pio(drive->regs, cmd, param);
+    if (ret)
+        return ret;
+    // Read/write data
+    u32 end = timer_calc(SDHCI_TRANSFER_TIMEOUT);
+    u16 cbit = isread ? SI_READ_READY : SI_WRITE_READY;
+    while (count--) {
+        ret = waitw(&drive->regs->irq_status, cbit, cbit, end);
+        if (ret)
+            return ret;
+        writew(&drive->regs->irq_status, cbit);
+        int i;
+        for (i=0; i<DISK_SECTOR_SIZE/4; i++) {
+            if (isread)
+                *(u32*)data = readl(&drive->regs->data);
+            else
+                writel(&drive->regs->data, *(u32*)data);
+            data += 4;
+        }
+    }
+    // Complete command
+    // XXX - SC_STOP_TRANSMISSION?
+    ret = waitw(&drive->regs->irq_status, SI_TRANS_DONE, SI_TRANS_DONE, end);
+    if (ret)
+        return ret;
+    writew(&drive->regs->irq_status, SI_TRANS_DONE);
+    return 0;
+}
+
+// Read/write a block of data to/from the card.
+static int
+sdcard_readwrite(struct disk_op_s *op, int iswrite)
+{
+    struct sddrive_s *drive = container_of(
+        op->drive_gf, struct sddrive_s, drive);
+    int cmd = iswrite ? SC_WRITE_SINGLE : SC_READ_SINGLE;
+    if (op->count > 1)
+        cmd = iswrite ? SC_WRITE_MULTIPLE : SC_READ_MULTIPLE;
+    int ret = sdcard_pio_transfer(drive, cmd, op->lba, op->buf_fl, op->count);
+    if (ret)
+        return DISK_RET_EBADTRACK;
+    return DISK_RET_SUCCESS;
+}
+
+int VISIBLE32FLAT
+process_sdcard_op(struct disk_op_s *op)
+{
+    if (!CONFIG_SDCARD)
+        return 0;
+    switch (op->command) {
+    case CMD_READ:
+        return sdcard_readwrite(op, 0);
+    case CMD_WRITE:
+        return sdcard_readwrite(op, 1);
+    case CMD_FORMAT:
+    case CMD_RESET:
+    case CMD_ISREADY:
+    case CMD_VERIFY:
+    case CMD_SEEK:
+        return DISK_RET_SUCCESS;
+    default:
+        return DISK_RET_EPARAM;
+    }
+}
+
+
+/****************************************************************
+ * Setup
+ ****************************************************************/
+
+// Initialize an SD card
+static int
+sdcard_card_setup(struct sdhci_s *regs)
+{
+    // XXX - works on QEMU; probably wont on real hardware!
+    u32 param[4] = { 0x01 };
+    int ret = sdcard_pio_app(regs, SC_APP_SEND_OP_COND, param);
+    if (ret)
+        return ret;
+    int card_type = (param[0] & SR_OCR_CCS) ? SF_SDHC : SF_SDSC;
+    param[0] = 0x00;
+    ret = sdcard_pio(regs, SC_ALL_SEND_CID, param);
+    if (ret)
+        return ret;
+    param[0] = 0x01 << 16;
+    ret = sdcard_pio(regs, SC_SEND_RELATIVE_ADDR, param);
+    if (ret)
+        return ret;
+    u16 rca = param[0] >> 16;
+    param[0] = rca << 16;
+    ret = sdcard_pio(regs, SC_SELECT_DESELECT_CARD, param);
+    if (ret)
+        return ret;
+    return card_type;
+}
+
+// Setup and configure an SD card controller
+static void
+sdcard_controller_setup(void *data)
+{
+    struct pci_device *pci = data;
+    u16 bdf = pci->bdf;
+    wait_preempt();  // Avoid pci_config_readl when preempting
+    struct sdhci_s *regs = (void*)pci_config_readl(bdf, PCI_BASE_ADDRESS_0);
+    pci_config_maskw(bdf, PCI_COMMAND, 0,
+                     PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
+
+    // Initialize controller
+    if (!runningOnQEMU())
+        // XXX - this init logic will probably only work on qemu!
+        return;
+    writew(&regs->irq_signal, 0);
+    writew(&regs->irq_enable, 0xffff);
+    writew(&regs->error_signal, 0);
+    writeb(&regs->power_control, 0x0f);
+    writew(&regs->clock_control, 0x0005);
+
+    // Initialize card
+    int card_type = sdcard_card_setup(regs);
+    if (card_type < 0)
+        return;
+
+    // Register drive
+    struct sddrive_s *drive = malloc_fseg(sizeof(*drive));
+    if (!drive) {
+        warn_noalloc();
+        return;
+    }
+    memset(drive, 0, sizeof(*drive));
+    drive->drive.type = DTYPE_SDCARD;
+    drive->drive.blksize = DISK_SECTOR_SIZE;
+    drive->drive.sectors = (u64)-1; // XXX
+    drive->regs = regs;
+    drive->card_type = card_type;
+
+    dprintf(1, "Found SD Card at %02x:%02x.%x\n"
+            , pci_bdf_to_bus(bdf), pci_bdf_to_dev(bdf), pci_bdf_to_fn(bdf));
+    char *desc = znprintf(MAXDESCSIZE, "SD Card"); // XXX
+    boot_add_hd(&drive->drive, desc, bootprio_find_pci_device(pci));
+}
+
+void
+sdcard_setup(void)
+{
+    if (!CONFIG_SDCARD)
+        return;
+
+    struct pci_device *pci;
+    foreachpci(pci) {
+        if (pci->class != PCI_CLASS_SYSTEM_SDHCI || pci->prog_if >= 2)
+            // Not an SDHCI controller following SDHCI spec
+            continue;
+        run_thread(sdcard_controller_setup, pci);
+    }
+}
diff --git a/src/post.c b/src/post.c
index 0fdd28e..9ea5620 100644
--- a/src/post.c
+++ b/src/post.c
@@ -143,6 +143,7 @@
     floppy_setup();
     ata_setup();
     ahci_setup();
+    sdcard_setup();
     cbfs_payload_setup();
     ramdisk_setup();
     virtio_blk_setup();
diff --git a/src/util.h b/src/util.h
index ed90e03..09bb8a9 100644
--- a/src/util.h
+++ b/src/util.h
@@ -146,6 +146,10 @@
 void ramdisk_setup(void);
 int process_ramdisk_op(struct disk_op_s *op);
 
+// hw/sdcard.c
+int process_sdcard_op(struct disk_op_s *op);
+void sdcard_setup(void);
+
 // hw/timer.c
 void timer_setup(void);
 void pmtimer_setup(u16 ioport);